1. Field of Invention
The present invention relates to the technical field of character input, specifically to handwriting input method, and more specifically to an overlapped handwriting input method.
2. Description of Related Arts
Recently, the handwriting input method, as an important character input manner, has been widely applied in various mobile electronic devices, such as a smart phone, a tablet computer, a netbook, a global positioning system (GPS) terminal, and a learning machine. The handwriting input method generally refers to that a user writes characters on a touch screen of an electronic device by using a handwriting pen or a finger, the electronic device recognizes collected tracks of the written characters, converts the tracks into corresponding characters, and displays the characters on the screen. During collecting the data of the handwritten tracks of the user, the electronic device usually displays the handwritten tracks of the user on a display screen in real time, so that the user can conveniently view track feedback information of strokes of the written characters in real time.
The touch screen and display screen of the current mobile electronic device has a limited size, especially in a new generation smart phone, such as an iPhone and an Android phone, the handwriting input is generally implemented by sensing a moving track of a human finger on a capacitive touch screen, and because of the limited size of the touch screen and limited resolution of the finger touch point, the user can only write one or two characters on the touch screen at a time, and the user, after finishing writing one character, usually has to stop for a while (the typical stop time is about 200 ms-1000 ms) and wait for the mobile device to perform detection and recognition of the latest written character before handwriting inputting the next character. In this way, the efficiency of character handwriting input is low, and the user cannot input continuous handwriting according to the user's natural writing practice.
In order to improve the handwriting input efficiency, related researchers developed a handwriting input solution of full-screen handwriting and full-screen recognition, in which several characters can be written on the touch screen at a time, and an image of all the written characters is submitted to a recognition engine for analysis and recognition. However, this method is still limited by the size of the touch screen, and cannot perform continuous writing of any number of characters (for example, writing of a complete sentence). Especially, on a mobile electronic device with a touch screen having a limited size (for example, a smart phone), the number of characters that can be written at a time on the full screen of the touch screen is generally small (for example, for an iPhone smart phone, the number of characters that can be written on a screen by using a finger is less than 4), moreover, if different characters are connected or overlapped when the user performs full-screen handwriting, the recognition engine may fail to correctly segment and recognize characters.
The present invention performs a character handwriting input method for continuous writing of any number of characters in an overlapped writing manner, thus effectively solves the above problems. The so-called overlapped writing manner refers to a manner that, the user, after finishing writing one character, can completely or partially overlap the next written character on the previous character. This method enables the user to write different characters without any pause, and multiple handwritten characters can be written continuously on a handwriting input screen and be correspondingly recognized, thereby greatly improving the efficiency of character handwriting input. However, a major problem of the method lies in that, during the overlapped writing, the existence of strokes of old characters interferes with the displaying of strokes of a newly written character on the touch screen (for example, the display of overlapped writing tracks of two characters “” shown in FIG. 1), which affects the display feedback to the user, causes visual interference on new writing track of the user, and reduces the user experience and input efficiency. The problem is especially severer when overlapped writing multiple characters continuously, for example, when continuously writing three characters “”, as shown in FIG. 3, the user can hardly see the track of strokes of the newly written character clearly when the user writes the third character “”.